DESCRIPTION: Caused by Borrelia burgdorferi, Lyme disease (LD) can affect the skin, heart, joints or nervous system leading to an array of largely non-specific symptoms that overlap with those of other debilitating illnesses. Disease progression can lead to development of conditions with unfavorable prognosis such as antibiotic-refractory arthritis or Post- Treatment Lyme disease Syndrome (PTLDS). Early diagnosis and treatment is key to improving disease outcomes. Current assays do not discriminate between early and late stages of the disease and cannot predict prognosis. We propose to use ultrasensitive microfluidics technology to develop the first quantitative rapid lab-on-a-chip point of care (POC) assay for the serodiagnosis of Lyme disease. The proposed POC test will provide sensitive and definitive detection and differentiation of early- and late- stage Lyme disease in a single test. It is a versatile and informative first-tier assay which can evolve to replace the current bi-serologic two-tier standard of care.